Numerous attempts have been made to produce satisfactory filtering devices for removing objectionable constituents from the exhaust gases of internal combustion engines. The filters of the prior art have been subject to two common mechanical faults, namely, channeling of the gases in the filter element whereby intimate contact between the gases to be filtered and the filter element is not achieved and a deterioration of the structure of the exhaust gas filter element due to the corrosive effects of the exhaust gases at the high temperatures involved.
The prior art discloses various filtering devices. Known in the prior art is Adiletta, U.S. Pat. No. 5,470,364, which discloses a diesel exhaust filter including a microporous filter for removing particulate contaminants. The filter material can be made of fibers or powders, such as high purity silica, aluminosilicate or boronsilicate-E glass.
Also known in the prior art is von Blucher et al., U.S. Pat. No. 4,906,263, which discloses an adsorption filter for removing undesirable gases or fluids. The filter includes a fixed bed of adsorber particles which are pourable and abrasion-resistant. The adsorber particles can be beads having a diameter of 0.1-1 mm. Diatomite is disclosed as being suitable for use.
Also known is Shiba et al., U.S. Pat. No. 6,423,534 B1, which discloses a method and apparatus for decomposing and eliminating ethanol in exhaust gas. The apparatus includes a filter material including a microorganism. The filter material for carrying the microorganism can be of diatomaceous earth.
Also known is Colvin et al., U.S. Pat. No. 3,933,643, which discloses electrically conductive filter elements including a carbonaceous conductive material and optionally other fibrous material, such as silica, or a bed-type filter, such as a diatomaceous earth.
Also known is Iida et al., U.S. Pat. No. 4,728,503, which discloses a filter medium for treating an exhaust gas including a porous ceramic substrate with a pre-coat layer to prevent clogging of the porous substrate, and a layer of slaked lime or calcium carbonate and calcium chloride. The pre-coat layer can be of a powder of diatomaceous earth.
Also known is Dufour, U.S. Pat. No. 5,179,062, which discloses a method of producing filtration agents. The method involves the calcination of diatomites in a circulated bed furnace to control agglomeration of the diatomaceous particles. Also known in the prior art relating to exhaust mufflers, including with perforated tubes and a particulate trap, are Jacobs et al., U.S. Pat. No. 3,960,528; Hoggatt, U.S. Pat. No. 4,318,720; Schuster et al., U.S. Pat. No. 5,223,009; and Herman et al., U.S. Pat. No. 5,246,472.
None of these patents disclose diatomites utilized with the muffler.
The present invention achieves a remedy to the prior art deficiencies noted above, and not addressed in the prior art, by a novel filter device and filtering system, and in particular a novel filter cartridge.